1. Field of the Invention
The present invention relates to restorative elements such as crowns which are attached to teeth and more particularly concerns a device for the placement, seating and cementation of a restorative element such as a crown onto a tooth.
2. Description of Related Information
Generally speaking, it is common dental practice to partially remove an exposed portion of a tooth such as molar or bicuspid. That portion of the tooth remaining is permanently engaged by a restorative element, such as a crown, which has substantially the same external configuration as the original tooth. The restorative element or crown is bonded to the remaining portion of the tooth using cement.
When placing a restorative element, such as a crown, onto a tooth, such as a molar, the dentist must assure that the crown is properly placed and seated and restrained in a seated position while the cement between the crown and the molar solidifies.
It is believed that dynamic loading is superior to static loading for seating and holding the crown during the cementation process. The dynamic loading works the crown into its proper seated position while expelling air and excess cement. Rosenstiel and Gegauff in their Journal of the American Dental Association article of Dec., 1988 demonstrate the superiority of dynamic seating methods over static seating methods for the cementation of complete cast crowns. Dynamic seating force can be applied with the use of an orange wood stick where the dentist and the patient work together to provide dynamic loading on the newly placed crown. In this procedure the dentist controls the orange wood stick while the patent provides a variety of biting forces on the stick, against the crown, as instructed by the dentist.
Zarro in U.S. Pat. No. 4,219,619 teaches a form of dynamic loading using a vibrator utilizing a disposable bite probe.
During the placement and cementation process which is demanding of the dentist's attention he or she must also be ever alert to the safety of the patient. A loose crown could accidentally be swallowed by the patient or, more seriously, be aspirated by the patient. Aspiration of a crown leads to serious medical complications with respect to the after effects of the aspiration and removal of the crown. Many cases of crown operation have been documented with some unfortunately leading to the death of the patient. Seals, Adry and Kellar in their Journal of the American Dental Association article of Oct., 1988 discuss pulmonary aspiration of a metal casting and the danger of ingesting or aspirating a foreign body by a patient during dental treatment. The article discusses the prevention and management of this event.
In addition, devices have been developed and are readily commercially available to help prevent ingestion and aspiration of foreign bodies during dental treatment. A rubber dam or sheet of plastic material is commonly used to cover the throat and airways in the rear of the mouth during dental procedures which have a high potential for generating debris. U.S. Pat. No. 4,664,628 to Totaro teaches such a device. These devices are very difficult to use and compromise the dentist's and the patient's ability to optimize the cementation process by occupying the limited space of the oral cavity, distracting the patient, severely limiting the patient's ability to provide biting forces, and limiting the space available for activities associated with the procedure.
The prior art has provided teachings and devices to provide for dynamic seating forces during the placement, seating and cementation of crowns and has also provided teachings and devices to help prevent the ingestion and aspiration of a foreign body during dental treatment. However, there is still a need for a simple, straight forward, reliable, easily fabricated device for the placement, seating and cementation of a restorative element onto a tooth which provides for the application of dynamic seating forces to the restorative element while helping to prevent aspiration or ingestion of the restorative element during the procedure.